39 
with guaiac on addition of hydrogen peroxid, and also shows at the 
same time catalytic action on hydrogen peroxid. This opinion, how- 
ever, had already been doubted by Jacoby, who assumes not only 
one but several oxidizing enzyms in the animal, and also holds that 
the agency oxidizing the sugar is different from that which oxidizes 
salicylic aldehyde to salicylic acid.* 
Quite recently F. Umber’ has asserted that the destruction of sugar 
by an extract of the pancreas gland is merely due to microbes, since 
it is not observed when antiseptic measures are resorted to. 
The inability of @- and f-catalase to produce a blue reaction with 
guaiac solution appears at first sight to be decisive against the assump- 
tion that these enzyms can bring on any oxidation; but this inference 
is not justifiable, since the action of the oxidizing enzyms is sometimes 
quite specific; that is, they act only on a certain group of bodies of a 
distinct chemical character or on compounds in which not only a cer- 
tain degree of lability, but also a configuration, is found that coincides 
in a certain measure with that of the oxidizing enzym. Griiss has 
recently observed an oxidizing enzym in barley grains which has no 
reaction on guaiac, but yields a violet color with tetramethylparaphe- 
nylendiamine. He calls it spermase.°* 
The indophenol reaction also can not be produced by catalase. This 
was tried: with a preparation from sweated tobacco and with one 
obtained by salting out the filtrate of a culture of Penicillium by 
ammonium sulphate. A trace of hydrogen peroxid in the control case 
sufficed to produce this blue color in the mixture of paraphenylen- 
diamine and a-naphthol in presence of sodium carbonate, even in the 
absence of oxidizing enzyms. . 
A characteristic oxidation by catalase, however, is produced with 
hydroquinone, the odor of quinone being developed within a very 
shorttime. This has been tried with (-catalase salted out from the juice 
of potatoes, with extract of poppy seed, with a concentrated extract 
of sweated tobacco, and, further, with tobacco that had been well 
extracted with water containing chloroform. This well-washed 
tobacco, containing a considerable amount of a-catalase, gave, after 
being moistened with a dilute solution of hydroquinone and stand- 
ing fifteen minutes, the characteristic quinone odor, which after 
? Virchow’s Archiv, vol. 157, p. 235 (1899). 
* Zeitschrift fur Klinische Medicin, vol. 39, p. 13 (1900). 
? Sometimes the reaction of the medium to be tested has to be carefully observed, 
since certain color reactions, as, for example, the indophenol reaction, succeed only in 
weak alkaline solution. Sometimes certain compounds may also be present which 
interfere with the production of the reaction. Thus, Epstein observed that the action 
of the oxidase contained in fresh juice of beets is prevented by the presence of prussic 
acid, and is restored when this is expelled by a current of air. This is also a deci- 
sive proof of the enzymatic nature of the oxidizing phenomena in fresh beet juice. 
(Archiv fur Hygiene, vol. 36, p. 140.) 
